I believe all friends who have come into contact with cars know that horsepower (power) and torque (torque) are often used to measure the engine power of a car. These two performance indicators have different opinions, and many people accept that "horsepower represents extreme speed and torque represents acceleration". There are also more experienced fans who believe in "horsepower selling, torque racing" (horsepower is used to sell cars and torque is used to race cars). What is the relationship between torque and horsepower, and what performance do they represent? The key is, which of them can better explain the performance of the car?

As we all know, the engine's job is to push the piston through the combustion of fuel in the cylinder, and the piston drives the crankshaft to rotate through the connecting rod, thus outputting power. This part of the output is the crankshaft torque. It can be said that the automobile is propelled and accelerated by transmitting the torque generated by the engine to the tires. Power is the work done by the engine in a unit time, which is simply understood as how far a car with a certain weight can be pushed in a certain time. Torque and horsepower can be converted by a simple formula:

Power (kW) = torque (Nm) * engine speed (rpm) ÷9550

In fact, the horsepower output by an automobile engine cannot be directly measured, but the torque can be directly measured. Therefore, both the laboratory and the Mali engine measure the torque output, and the horsepower is obtained by converting the torque output and the engine speed at that time with the above formula. In fact, the engine not only outputs torque, but also outputs engine speed, which is closely related to the speed and power of the car. The engine power obtained by the combination of torque and engine speed more describes the ability of the engine to change the crankshaft speed at a certain speed.

Although torque is the most fundamental force produced by the engine, it has different effects on the performance of the car because of its relationship with the vehicle speed. Usually, the dynamic performance of automobile is discussed from two aspects: limit speed and acceleration. As we know, acceleration = force/mass, so the acceleration force of a car is determined by torque. However, people often ignore a problem, even if the torque of automobile acceleration is the torque at the wheel end, not directly driven by the torque of the engine. Because the torque of the engine is really small, the smart car designer designed the "gearbox".

However, due to the low engine speed, the transmission ratio of the gearbox is very small, which can not meet the normal driving speed. Therefore, the torque on the wheel is actually not large, and the acceleration ability is not as strong as expected. Finally, to sum up, the maximum power of the same car determines the extreme speed performance and acceleration performance of the car, and the maximum torque and its speed express the active range of the engine. The former indicates performance, while the latter indicates practicality. Next time you see torque and horsepower, you won't be fooled again.